blue hawaii build transormer and psu questions.

[jamesmking]

Hi all,

Im planning to build a blue hawaiii using the version 6s bipolar amp boards (kgbhver6sbipolar.zip) and the  kgsshv dual 2 new power supply, (kgsshvpssicfetdual2new.zip)

Gerber files are in 

https://drive.google.com/drive/folders/0B_iJFfZStuVhSE5nOHBVdTByR1k

Has anyone tried this combination? will the psu provide sufficent current (the voltages are fine +-400V -+15V and 580V)

Does anyone know what ratings I need for the transformer

Im guessing for the secondaries

2x 6.3 5A  (el34s draw about 1.5A each plus I want plenty of headroom)

2x 360V 230mA

18-0-18V 200mA

Does the kgsshvpssicfetdual2new offer delayed start for the +-400V?

Is it robust and have any form of short circuit protection on its outputs?

Sorry to ask so many questions. I could not find circuit diagrams for the kgbhver6sbipolar or the kgsshvpssicfetdual2new.. so I have been reverse engineering from the gerber files... which is not fun and a slow process...

regards

James

 

 

[mwl168]

If you can post the PCB image of the Gerber file for the PSU it would help answer your question about the HV delay.

If you want plenty of headroom for the secondaries I would go with 300mA for the HV secondaries. On the Blue Hawaii, the negative rail draws much higher current (somewhere around 130mA IIRC) than the positive rail. The front end JFETs draw very little current so 200mA should be fine.

Assuming the PSU boards you are targeting is what commonly known here as the GRHV,  I don't think you need 360vac secondaries if you are planning for 400VDC regulated rails. 330vac should provide enough headroom for dropout voltage. It's a different story if you are using the earlier PSU that was designed for the KGSSHV.

 

Edited August 2, 2019 by mwl168

[jamesmking]

Thank you for the quick reply. This is a more or less direct reverse engineer of the psu pcb. I have only just completed it so there may well be errors....

[mwl168]

This look to be a version of the GRHV without the soft-start HV feature. Look for the later Gerber files that contain a CPC1117N part. Also search the threads for the information of implementation of the HV delay. 

[jamesmking]

Thanks, I found it, v1.8 has the cpc117n the board I reverse enginerred is v1.7...

There seems to be no dual rail single board version with the cpc117n v 1.7 is the latest I can find. But looking at the differences in the +400 "right board" v 1.7 and 1.8 the only differences are the cpc117n and a few component moves to fit it in. so it should not be too hard to modify the version 1.7 dual to 1.8...

 

 

[thuytn]

Is this the board you are looking at? I'm also thinking of having some boards made but notice the PZTAs are in to-220 package, not to-92 or smd. 

Probably there is a newer revision but I couldn't find it until now. 

I'm also interested in a dual rails single board GRHV with soft-start.

 

[jamesmking]

Yes that is the blue hawaii amp board I plan to use. I have no checked component availability for it yet. I want to build the PSU first and have ordered all the parts fot eh psu. I have 5 psu and 5 amp boards on order from JLPCB, the boards will be black and with gold pads ? . Its too late for me to cancel the psu order so my psu will not have the cpc1117N for delayed start ?  . But I plan to put a 555N and relay before the 360VAC inputs and implement delayed start that way - its the method my alpha centauri amp uses.

I have updated the 1.7 psu board to have cpc1117N soft start, I did it *late* last night but have not had a chance to check it yet... Im off to rock climbing in a few minutes. You are welcome to the gerber files if you want them, if you can check them even better.... if they are correct maybe the stax mafia could add them to the archive.... (I think its only fair us dual psu people get the same functionality as the singles) ? ? .....

I also have a reverse enginer of the circuit for the amp board... again not checked.... if someone wants to check the schematics maybe the stax mafia would be interested in them too?

(when I do a build I like to have circuit diagrams)... makes troubleshooting far far easier.

regards

James

 

 

This is my reverse engineer of the amp board thuytn posted. it is NOT checked. This is the version of the Blue Hawaii Kevin Gilmore recommended I build....

[thuytn]

James,

I’d love to have a look at the gerber.

Also from the amp board, I can’t find the 470r resistors connected to G2. From what I saw from others’ builds, looks like there’s a newer revision.

[mwl168]

You can retro-fit the HV soft start circuit quite easily on earlier boards. A few here have done it successfully.

PZTAx6 parts are SMD, not through-hole package. They are meant to be mount vertically on some of boards Kevin laid out.

The threads are your friend, these information is all there. Read them thoroughly.

[jamesmking]

On 8/3/2019 at 9:25 AM, thuytn said:

James,

I’d love to have a look at the gerber.

Also from the amp board, I can’t find the 470r resistors connected to G2. From what I saw from others’ builds, looks like there’s a newer revision.

Well spotted I didnt notice that, your amp board is slightly different from my one...  I wish there was version numbers on the pcb for the amp board... my board comes from the file  kgbhver6sbipolar.zip. 

your board has 5V ac for the heaters rather than 6.3... so I think it might be the directly heated  triode version of kgbhver6sbipolar.zip which is kgbhver6sbipolardht.zip.....

ugh howmanywordscantheyputonafilenamebeforeusingunderscores???

maybe this thread needs renaming to "blue_hawaii_newbees_trying_to_understand_the_different_versions"... ?

 

[kevin gilmore]

the dht version is for the emission labs directly heated triodes. Expensive and requires 4 separate 5v filament windings on the transformer.

[jamesmking]

Thanks Kevin. Im sticking to 6.3VAC non directly heated

 

[jamesmking]

updated soft start, slightly shorter with 3 more standoffs and a vent hole for the 1n4007